Field notes · GNSS & grids · 6 min
Your grid is not your QRZ zip code. Stop logging as if it were.
Distance and azimuth only mean something if the logger knows where you actually are. A phone GNSS can write a six-character Maidenhead at QSO time. A profile page cannot.
2026-09-26 UTC
Grid at QSO time
You walk. The park is large. The summit ridge is not the activation zone you started in. The grid that belongs in the ADIF is the one at the moment of the contact, not the one on your QRZ biography.
FN42pr, not a guess. On-device computation. No map tiles required.
Azimuth that is not a zip code
Every callsign can return distance and bearing from your actual position. That is useful for a beam, a wire heading, and a sanity check when someone is “local” and 800 km away. It is noise if the logger thinks you are still at home.
- GNSS first. Manual grid second.
- Store the lock with the QSO.
- Degrade to vector/grid when basemaps cannot load.
Geofence is a courtesy, not magic
Walking into a POTA park and having the reference appear is good UX. It is not a substitute for knowing the reference you intended to activate. Confirm it. Then let GPS keep the grid honest while you run.
Why this belongs in the logger
A separate GPS app means you will not look at it during a pileup. Log73 treats GNSS as a log field. Field trial is for people who have already uploaded the wrong grid and did not enjoy the QSL mail.
Questions
Should I log a 4-character or 6-character grid?
Six when GNSS is locked. Four is a fallback. Store the lock you had at QSO time even if you walk afterward.
What if GPS fails in a canyon?
Enter a grid manually and keep logging. DUPE, radio, and weather should not depend on a fix.
Log73 is in field trial.
Request a slot. Bring a radio.